In recent years, organic electroluminescence (EL) display devices, which use organic EL elements and are of the self-luminous type, have attracted attention as a display device that can replace the liquid crystal display device. A general organic EL display device is provided with a sealing film covering the organic EL element to inhibit degradation of the organic EL element due to penetration of, for example, moisture and oxygen.
For example, PTL 1 discloses a method of manufacturing an organic EL element through a process of patterning the sealing film, which is achieved by performing a dry etching process using a metal mask to remove some part of the sealing film.